A look at release of the immigrant charged in pier killing

SAN FRANCISCO (AP) — The city of San Francisco has come under fire after it released a Mexican immigrant in the country illegally despite a request by federal immigration authorities to keep him in custody so they could deport him for a sixth time.

Juan Francisco Lopez Sanchez, who has four prior felony drug convictions, is now charged with murder in the killing last week of a woman at a city pier. He has pleaded not guilty.

San Francisco does not honor requests from immigration authorities to hold individuals in custody. The city is one of dozens of communities in the nation that don't fully cooperate with the requests known as detainers, which are used to hold arrestees once their criminal cases have concluded so officials can seek to deport them.

Here are some things to know about the case:

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WHY WAS SANCHEZ IN THE SAN FRANCISCO JAIL?

Sanchez pleaded guilty in 2011 to illegally re-entering the U.S. after having been deported and was sentenced to nearly four years in federal prison. He was finishing up his sentence when he was turned over in March to the San Francisco Sheriff's Department on a 20-year-old drug charge.

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HOW DID HE GET RELEASED?

U.S. Immigration and Customs Enforcement issued a detainer asking San Francisco authorities to keep Sanchez in custody so he could be deported again after the drug case was resolved. The detainer was issued, immigration authorities say, because immigration violations are administrative, not criminal.

San Francisco Sheriff Ross Mirkarimi said his office routinely ignores the detainers unless they are backed by an arrest warrant. He said ICE was aware of San Francisco's policy. Sanchez was released after prosecutors eventually dismissed the drug case because it was so old and involved a small amount of marijuana.

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WHY DON'T SOME COMMUNITIES FULLY COMPLY WITH IMMIGRATION DETAINERS?

Many jurisdictions believe the detainers erode police relations with immigrant communities by making people reluctant to report crimes. The criticism increased after the federal government rolled out its Secure Communities program, giving immigration agents access to information about arrestees booked into local jails.

Advocates rallied against the program when some immigrants found themselves facing deportation after being arrested on minor charges, and California passed a law limiting when detainers could be honored.

Last year, a number of jurisdictions stopped releasing arrestees to ICE altogether after a federal court ruling in Oregon found a woman's rights were violated when she was held in jail without probable cause.

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WHAT IS AN IMMIGRATION DETAINER?

Detainers call for a law enforcement agency to hold people for as long as 48 hours beyond their release date until they can be picked up by ICE. Since some agencies have stopped honoring the detainers, ICE has started asking in some instances for notification by police when arrestees are going to be released.

The agency also has said it will focus on detaining immigrants who are convicted of serious crimes or pose a threat to public safety.